Module: Dynomite::Item::Locking

Extended by:
ActiveSupport::Concern
Included in:
Components
Defined in:
lib/dynomite/item/locking.rb

Instance Method Summary collapse

Instance Method Details

#increment_lock_version ⇒ Object 



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# File 'lib/dynomite/item/locking.rb', line 25

def increment_lock_version
  return unless changed?
  reader = self.class.locking_field_name
  setter = "#{reader}="
  send(setter, 0) if send(reader).nil?
  send(setter, send(reader) + 1)
end

#reset_lock_version_was ⇒ Object

Tricky: Must use dot notation for dirty tracking so old values are stored in case of a exceptional failure in the DynamoDB API put_item call in write/save.rb Example:

post.update_attribute(:title, nil) # update attribute bypasses validations

AWS Error:

The AttributeValue for a key attribute cannot contain an empty string value. IndexName: title-index, IndexKey: title (Aws::DynamoDB::Errors::ValidationException)

This allows the old value to be restored. And then the next update with a corrected title value saves successfully.



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# File 'lib/dynomite/item/locking.rb', line 47

def reset_lock_version_was
  reader = self.class.locking_field_name
  setter = "#{reader}="
  send(setter, send("#{reader}_was"))
end